Impaired fatty acid synthesis was noted in iron deficient animal models. Human data, however, are scarce. Although Canadian Inuit have a traditional diet rich in heme iron and long chain n-3 fatty acids, recent literature has also indicated the presence of prevalent iron deficiency. We aimed to explore whether the presence of iron deficiency would affect fatty acid status and an estimate of the activity of desaturase 5 (Δ5), which is crucial in the biosynthesis of highly unsaturated n-3 fatty acids among Canadian Inuit. Erythrocyte membrane fatty acid composition was utilized as an indicator of fatty acid status and serum ferritin and circulating hemoglobin level were measured as the indicators of iron status. Data analyzed were collected among 1511 Canadian Inuit adult participants in the International Polar Year Inuit Health Survey, 2007-2008. Only 13.7% of survey participants had iron deficiency; however, serum ferritin showed a moderate positive association with highly unsaturated n-3 fatty acids after adjusting for age, waist and C-reactive protein (r = 0.172, P < .0001). Serum ferritin correlated significantly with Δ5 after further adjusting for highly unsaturated n-3 fatty acids (r = 0.126, P < .0001). Although the current study only demonstrated a weak link between ferritin and Δ5, the latter association underscores a possible health risk caused by a nutrient interaction related to reduced iron intake and decreased highly unsaturated n-3 fatty acid biosynthesis. Future studies are recommended to evaluate iron status in relation to highly unsaturated n-3 fatty acid biosynthesis and status among indigenous people undergoing rapid dietary transitions.